Human Biology 2.2 Passive Transport

Passive Transport

transporting material through a membrane that does not require energy

Concentration Gradient

area of high concentration of a substance adjacent to a low concentration area

Diffusion

molecules moving from an area of high concentration to an area of low concentration

Facilitated Diffusion

diffusion that occurs with the help of membrane proteins

necessary when transporting polar molecules, cell membrane’s hydrophobic parts would typically repel

Transport Proteins

membrane protein that allows a substance to pass through by binding to it

Channel Protein

membrane protein that allows a substance to pass through the membrane by going through the protein’s hollow core

Aquaporin

channel protein that allows water to pass through a membrane at a very high rate

Carrier Protein

membrane protein that allows a substance to pass through by changing it’s shape when the substance binds to it

Osmosis

movement of water molecules through a semipermeable membrane

Semipermeable Membrane

membrane that allows only water to pass through

Tonicity

the capability of a solution to modify the volume of a cell depending on its concentration

water moves in or out of cell

Osmolarity

total amount of solutes dissolved in a specific solution

Hypotonic

higher concentration of solute inside of cell

water moves into cell membrane

Hypertonic

higher concentration of solute outside of the cell

water moves out of the cell membrane

Isotonic

concentration of solute is equal inside and outside of cell

water moves freely across membrane